/* ==========================================================================
   TTGO T-Call SIM800L V1.4 — Audio Fix Guide
   Dark "Aero" glass-over-water theme: frosted translucent panels, specular
   rim highlights, and deep-blue glows. Dark by default; light available via
   the theme toggle. No external dependencies.
   ========================================================================== */

:root {
  color-scheme: dark;

  /* Deep-water backdrop */
  --bg: #01050e;
  --water-1: rgba(16, 62, 160, 0.6);
  --water-2: rgba(24, 128, 200, 0.34);
  --water-3: rgba(88, 40, 190, 0.32);
  --water-blur: 46px;

  /* Glass surfaces */
  --paper: rgba(255, 255, 255, 0.055);
  --paper-strong: rgba(255, 255, 255, 0.085);
  --paper-muted: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.12);
  --glass-border-strong: rgba(255, 255, 255, 0.2);
  --rim: inset 0 1px 0 rgba(255, 255, 255, 0.26);
  --rim-soft: inset 0 1px 0 rgba(255, 255, 255, 0.16);
  --blur: saturate(170%) blur(20px);
  --sheen: linear-gradient(180deg, rgba(255, 255, 255, 0.22), rgba(255, 255, 255, 0) 46%);

  /* Ink */
  --ink: #eaf2fd;
  --ink-soft: #a9c1de;
  --ink-faint: #6f89ad;

  /* Accent (glowing sky/cyan) */
  --accent: #4aa8ff;
  --accent-deep: #7cc4ff;
  --accent-soft: rgba(74, 168, 255, 0.16);
  --accent-glow: rgba(74, 168, 255, 0.45);
  --accent-sheen: linear-gradient(180deg, rgba(255, 255, 255, 0.35), rgba(255, 255, 255, 0) 55%);

  /* Warning */
  --warning: #ffab6b;
  --warning-soft: rgba(255, 150, 80, 0.14);

  /* Code block (deeper glass pane) */
  --code-bg: rgba(3, 8, 20, 0.66);
  --code-border: rgba(255, 255, 255, 0.1);
  --code-ink: #e8f0fb;
  --code-muted: #7f97b8;
  --code-btn-border: rgba(255, 255, 255, 0.2);
  --code-directive: #5fd0e6;
  --code-number: #ffcf7a;
  --code-keyword: #c3a6f7;
  --code-function: #8fe0a8;
  --code-string: #f7b7cc;

  /* Effects */
  --shadow: 0 22px 50px rgba(0, 0, 0, 0.45);
  --shadow-glossy: 0 24px 55px rgba(0, 0, 0, 0.5);
  --radius: 18px;
}

:root[data-theme="light"] {
  color-scheme: light;

  /* Water backdrop (vivid, so the Aero blur shows through the glass) */
  --bg: #d7e4f6;
  --water-1: rgba(20, 92, 235, 0.9);
  --water-2: rgba(0, 122, 176, 0.82);
  --water-3: rgba(120, 60, 245, 0.62);
  --water-blur: 30px;

  /* Glass surfaces (more translucent so water refracts through) */
  --paper: rgba(255, 255, 255, 0.34);
  --paper-strong: rgba(255, 255, 255, 0.46);
  --paper-muted: rgba(255, 255, 255, 0.26);
  --glass-border: rgba(255, 255, 255, 0.6);
  --glass-border-strong: rgba(255, 255, 255, 0.82);
  --rim: inset 0 1px 0 rgba(255, 255, 255, 0.9);
  --rim-soft: inset 0 1px 0 rgba(255, 255, 255, 0.6);
  --blur: saturate(170%) blur(20px);
  --sheen: linear-gradient(180deg, rgba(255, 255, 255, 0.62), rgba(255, 255, 255, 0) 44%);

  /* Ink */
  --ink: #0a1f3c;
  --ink-soft: #3d5877;
  --ink-faint: #647fa3;

  /* Accent */
  --accent: #1667d3;
  --accent-deep: #0b4bab;
  --accent-soft: rgba(22, 103, 211, 0.12);
  --accent-glow: rgba(22, 103, 211, 0.28);
  --accent-sheen: linear-gradient(180deg, rgba(255, 255, 255, 0.55), rgba(255, 255, 255, 0) 55%);

  /* Warning */
  --warning: #c0562a;
  --warning-soft: rgba(192, 86, 42, 0.12);

  /* Code block stays a deep glass pane */
  --code-bg: rgba(6, 15, 32, 0.72);
  --code-border: rgba(255, 255, 255, 0.14);
  --code-ink: #e8f0fb;
  --code-muted: #8aa2c4;
  --code-btn-border: rgba(255, 255, 255, 0.28);

  /* Effects */
  --shadow: 0 22px 50px rgba(10, 31, 60, 0.16);
  --shadow-glossy: 0 24px 55px rgba(10, 31, 60, 0.18);
}


* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  position: relative;
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  isolation: isolate;
}

/* --- Animated "water" glow layer behind everything ---------------------- */
body::before {
  content: "";
  position: fixed;
  inset: -30vmax;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(34vmax 34vmax at 18% 20%, var(--water-1), transparent 55%),
    radial-gradient(38vmax 38vmax at 82% 24%, var(--water-2), transparent 56%),
    radial-gradient(42vmax 42vmax at 50% 92%, var(--water-3), transparent 54%);
  filter: blur(var(--water-blur));
  animation: water-drift 26s ease-in-out infinite alternate;
}

/* subtle specular sweep, like light on the water surface */
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: linear-gradient(120deg, rgba(255, 255, 255, 0.09), transparent 30%, transparent 70%, rgba(255, 255, 255, 0.07));
}

@keyframes water-drift {
  0%   { transform: translate3d(0, 0, 0) scale(1); }
  50%  { transform: translate3d(2%, -2%, 0) scale(1.06); }
  100% { transform: translate3d(-2%, 2%, 0) scale(1); }
}

@media (prefers-reduced-motion: reduce) {
  body::before { animation: none; }
  html { scroll-behavior: auto; }
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

.page-shell {
  width: min(100% - 2rem, 1000px);
  margin: 0 auto;
}

/* -------------------------------------------------------------- Header -- */
.site-header {
  padding: 1.25rem 0 5.5rem;
}

.utility-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 2.5rem;
}

.utility-rule {
  display: block;
  width: 3.5rem;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent-deep));
  box-shadow: 0 2px 14px var(--accent-glow);
}

.theme-toggle {
  position: relative;
  display: grid;
  width: 2.75rem;
  height: 2.75rem;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 50%;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.30), rgba(255, 255, 255, 0) 48%),
    linear-gradient(155deg, #1d55a3 0%, #0e2f5e 52%, #08183a 100%);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.35),
    inset 0 -2px 6px rgba(0, 0, 0, 0.35),
    0 10px 22px rgba(3, 14, 36, 0.5);
  color: #a9d6ff;
  cursor: pointer;
  transition: transform 160ms ease, box-shadow 160ms ease, color 160ms ease;
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
  color: #eaf5ff;
  outline: none;
  transform: translateY(-1px);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.45),
    inset 0 -2px 6px rgba(0, 0, 0, 0.35),
    0 0 0 4px var(--accent-glow),
    0 12px 26px rgba(3, 14, 36, 0.55);
}

.theme-toggle:active {
  transform: translateY(0);
}

.theme-icon {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 1.25rem;
  height: 1.25rem;
  transition: opacity 200ms ease, transform 320ms ease;
}

/* Dark mode (default): show the sun — the action switches to light */
.icon-sun {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.icon-moon {
  opacity: 0;
  transform: rotate(-90deg) scale(0.6);
}

/* Light mode: show the moon — the action switches to dark */
:root[data-theme="light"] .icon-sun {
  opacity: 0;
  transform: rotate(90deg) scale(0.6);
}

:root[data-theme="light"] .icon-moon {
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.hero {
  max-width: 850px;
  padding-top: 5.75rem;
}

.eyebrow,
.code-language,
.section-number,
.site-footer,
.theme-toggle,
.copy-button {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 1.25rem;
  padding: 0.3rem 0.75rem;
  border: 1px solid var(--glass-border-strong);
  border-radius: 999px;
  background: var(--accent-sheen), var(--accent-soft);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  box-shadow: var(--rim-soft);
  color: var(--accent-deep);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  max-width: 820px;
  margin-bottom: 1.35rem;
  background: linear-gradient(180deg, var(--ink) 10%, var(--accent-deep) 120%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  -webkit-text-fill-color: transparent;
  font-size: clamp(2.25rem, 5.5vw, 4.45rem);
  font-weight: 800;
  letter-spacing: -0.055em;
  line-height: 1.04;
}

.subtitle {
  max-width: 620px;
  margin-bottom: 0;
  color: var(--ink-soft);
  font-size: clamp(1rem, 1.7vw, 1.2rem);
  line-height: 1.6;
}


/* ------------------------------------------------------------ Document -- */
.document {
  display: flex;
  flex-direction: column;
  gap: 5rem;
  padding: 0 0 5.5rem;
}

.doc-section {
  position: relative;
}

.section-heading {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid var(--glass-border);
  padding-bottom: 0.85rem;
}

.section-number {
  flex: 0 0 auto;
  color: var(--accent);
  font-size: 0.73rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.section-number-warning {
  color: var(--warning);
}

h2 {
  margin-bottom: 0;
  font-size: clamp(1.35rem, 3vw, 1.8rem);
  letter-spacing: -0.035em;
  line-height: 1.2;
}

/* ---------------------------------------------------------- Code block -- */
.code-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--code-border);
  border-radius: var(--radius);
  background: var(--code-bg);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  box-shadow: var(--rim-soft), var(--shadow-glossy), 0 0 70px rgba(56, 132, 255, 0.12);
}

/* glossy top sheen across the whole card */
.code-card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--accent), var(--accent-deep), transparent);
  box-shadow: 0 0 18px var(--accent-glow);
}

.code-toolbar {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 3.25rem;
  border-bottom: 1px solid var(--code-border);
  padding: 0.55rem 0.75rem 0.55rem 1.2rem;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0) 70%);
}

.code-language {
  color: var(--code-muted);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.copy-button {
  border: 1px solid var(--code-btn-border);
  border-radius: 8px;
  padding: 0.4rem 0.78rem;
  background: linear-gradient(180deg, rgba(125, 190, 255, 0.2), rgba(125, 190, 255, 0.06));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.22);
  color: var(--code-ink);
  cursor: pointer;
  font-size: 0.7rem;
  transition: background 160ms ease, border-color 160ms ease, color 160ms ease, box-shadow 160ms ease;
}

.copy-button:hover,
.copy-button:focus-visible {
  border-color: var(--code-directive);
  background: linear-gradient(180deg, rgba(95, 208, 230, 0.28), rgba(95, 208, 230, 0.08));
  color: var(--code-directive);
  outline: none;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.28), 0 0 0 3px rgba(95, 208, 230, 0.2);
}

.copy-button.is-copied {
  border-color: var(--code-function);
  color: var(--code-function);
}

.code-block {
  overflow-x: auto;
  margin: 0;
  padding: 1.35rem 1.2rem 1.5rem;
  color: var(--code-ink);
  font: 0.84rem/1.8 "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  tab-size: 2;
}

.code-line {
  display: block;
  min-width: max-content;
}

.token.directive { color: var(--code-directive); }
.token.number { color: var(--code-number); }
.token.keyword { color: var(--code-keyword); }
.token.function { color: var(--code-function); }
.token.string { color: var(--code-string); }


/* ------------------------------------------------------------ Callouts -- */
.callout {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.85rem;
  margin-top: 1.25rem;
  border: 1px solid var(--glass-border);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.1rem 1.2rem;
  background: var(--sheen), var(--paper);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  box-shadow: var(--rim-soft), 0 12px 30px rgba(0, 0, 0, 0.22);
}

.callout p,
.callout ul {
  margin: 0;
}

.callout-mark {
  display: grid;
  width: 1.5rem;
  height: 1.5rem;
  place-items: center;
  border: 1px solid var(--glass-border-strong);
  border-radius: 50%;
  background: var(--accent-sheen), var(--accent-soft);
  box-shadow: var(--rim-soft);
  color: var(--accent-deep);
  font-family: Georgia, serif;
  font-size: 0.85rem;
  font-weight: 700;
  line-height: 1;
}

.callout-warning {
  border-color: color-mix(in srgb, var(--warning) 45%, var(--glass-border));
  border-left-color: var(--warning);
  background:
    linear-gradient(180deg, color-mix(in srgb, var(--warning) 14%, transparent), transparent 45%),
    var(--warning-soft);
}

.callout-warning .callout-mark {
  color: var(--warning);
  background: linear-gradient(180deg, color-mix(in srgb, var(--warning) 30%, transparent), transparent 60%);
}

/* --------------------------------------------------------------- Table -- */
.table-wrap {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  background: var(--sheen), var(--paper);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  box-shadow: var(--rim-soft), var(--shadow);
}

table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

th,
td {
  padding: 0.9rem 1.1rem;
}

th {
  border-bottom: 1px solid var(--glass-border);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0) 70%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.14);
  color: var(--ink-soft);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

td {
  border-bottom: 1px solid var(--glass-border);
}

tbody tr:last-child td {
  border-bottom: 0;
}

td code,
.command {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

td code {
  color: var(--accent-deep);
  font-size: 0.92rem;
}

/* ------------------------------------------------------- Audio settings -- */
.settings-list {
  border-top: 1px solid var(--glass-border);
}

.setting-row {
  display: grid;
  grid-template-columns: minmax(10rem, 0.32fr) 1fr;
  gap: 2rem;
  align-items: baseline;
  border-bottom: 1px solid var(--glass-border);
  padding: 1.3rem 0;
}

.command {
  display: inline-block;
  border: 1px solid var(--glass-border-strong);
  border-radius: 8px;
  padding: 0.3rem 0.65rem;
  background: var(--accent-sheen), var(--accent-soft);
  -webkit-backdrop-filter: var(--blur);
  backdrop-filter: var(--blur);
  box-shadow: var(--rim-soft), 0 6px 18px rgba(0, 0, 0, 0.18);
  color: var(--accent-deep);
  font-size: 0.93rem;
  font-weight: 700;
  white-space: nowrap;
}

.setting-row p {
  margin: 0;
  color: var(--ink-soft);
}

/* ---------------------------------------------------------------- Tips -- */
.tips-list,
.callout-warning ul {
  margin: 0;
  padding-left: 1.3rem;
}

.tips-list li,
.callout-warning li {
  margin: 0.8rem 0;
  padding-left: 0.4rem;
}

.tips-list li::marker {
  color: var(--accent);
}

.callout-warning li::marker {
  color: var(--warning);
}

/* -------------------------------------------------------------- Footer -- */
.site-footer {
  border-top: 1px solid var(--glass-border);
  padding: 2rem 0 3rem;
  color: var(--ink-faint);
  font-size: 0.76rem;
  line-height: 1.8;
}

.site-footer p {
  margin-bottom: 0.25rem;
}

.site-footer a {
  color: var(--accent-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

.site-footer a:hover,
.site-footer a:focus-visible {
  color: var(--accent);
}

/* ----------------------------------------------------------- Responsive -- */
@media (max-width: 640px) {
  .page-shell {
    width: min(100% - 1.25rem, 1000px);
  }

  .site-header {
    padding-bottom: 4rem;
  }

  .hero {
    padding-top: 4.5rem;
  }

  h1 {
    font-size: clamp(2.2rem, 12vw, 3.5rem);
  }

  .document {
    gap: 4rem;
    padding-bottom: 4rem;
  }

  .section-heading {
    gap: 0.7rem;
  }

  .section-number {
    font-size: 0.66rem;
  }

  .code-block {
    padding-right: 1rem;
    padding-left: 1rem;
    font-size: 0.75rem;
  }

  .callout {
    padding: 1rem;
  }

  .setting-row {
    display: block;
  }

  .setting-row .command {
    display: inline-block;
    margin-bottom: 0.65rem;
  }
}